Obesity rates have had scientists worried for a while now. According to the State of Obesity, in the US alone, adult obesity rates as of September 2018 exceeded 35% in seven states, 30% in 29 states and 25% in 48 states.

Furthermore, research about the subject is complex and takes into account many factors. For instance, some studies point to DNA factors while others reveal even such trivial things as household cleaners could contribute to obesity.

Public transport and obesity

Now, two more studies released this week are bringing more information to the table. The first argues that public transportation systems could be responsible for lower obesity rates.

The research saw 227 US counties from 45 states analyzed to find that a percentage-point increase in mass transit ridership was associated with a 0.473 percentage-point lower obesity rate in the county. The county data was from 2001 and 2009.

“Opting for mass transit over driving creates opportunities for exercise that may otherwise not exist,” said Sheldon H. Jacobson, a co-author of the study and a Founder Professor of Computer Science at Illinois.

“Instead of just stepping out of the house and into his car, riders need to walk from their home to a bus stop and from their stop to their destination.”

However, the researchers also pointed out that the analysis may not directly apply to individuals. “Because this analysis is at the county level, the implications for an average person are not clear,” Jacobson said. 

“The results indicate that when more people opt to use public transit, the county-level obesity rate tends to drop, though it does not necessarily imply that any one particular person is less likely to be obese if they ride transit frequently.”

The study is published in the journal Transportation Research Part A: Policy and Practice.

Slow or fast?

Meanwhile, the second study looked at the rate of which weight loss is achieved to find its effect on overall health. The rate at which losing weight should happen has been a complicated subject so far.

Faster weight loss has been associated with a higher risk for gallstones but better for avoiding cardiovascular diseases and diabetes. However, the common recommendation for losing weight remains only one to two pounds per week.

What the researchers concluded in their work was that despite the improvements in health associated with faster weight loss being present, these were abolished after adjusting for absolute weight loss.

“With the same pound for pound weight loss, there is no difference in terms of health benefits if you lose weight fast or slow,” said study lead Jennifer Kuk, associate professor in York University’s Faculty of Health. 

“However, given the risk for gallstones with faster weight loss, trying to lose weight at the recommended one to two pounds per week is the safer option.” 

Although, the researchers did, in the end, recommend the slower safer option, they also advised that more research needed to be done to focus on long term weight goals.

“The results show that we really need to look at interventions that focus on long-term weight management that can achieve sustained weight loss at the recommended one to two pounds per week,” Kuk added.

The study, that looked at 11,283 patients who attended the Wharton Medical Clinic Weight Management Program between July 2008 and July 2017, is the first of its kind to take cardiovascular health and diabetes into account.

The study is published today in the Journal of Obesity.